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» CVE-2021-43812
The Auth0 Next.js SDK is a library for implementing user authentication in Next.js applications. Versions before 1.6.2 do not filter out certain returnTo parameter values from the login url, which expose the application to an open redirect vulnerability. Users are advised to upgrade as soon as possible. There are no known workarounds for this issue.
NVD Status： Modified ，CVE State: published
Threat Intelligence & Risk Assessment for CVE-2021-43812
Conclusion & alert: CVE-2021-43812 is rated Low Risk (39.1/100) : CVSS Medium severity, with low exploitation likelihood (EPSS 0.18%).Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2021-43812
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
#
Date
Old EPSS score
New EPSS score
Delta (New - Old)
1
2025-03-17
0.05%
0.18%
+0.13%
2
2023-03-07
0.89%
0.05%
-0.83%
3
2022-02-04
—
0.89%
—
Full EPSS history
(4 records total)
Common vulnerability scoring system (CVSS) metrics for CVE-2021-43812
CVSS metrics for this CVE.
Base score
Version
Severity
Vector
Exploitability
Impact
Score source
6.4
3.1
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
3.1
2.7
[email protected]
6.1
3.1
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8
2.7
[email protected]
5.8
2.0
MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N
Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
8.6
4.9
[email protected]
Weakness enumeration for CVE-2021-43812
GitHub Security Advisory for CVE-2021-43812
GHSA-2mqv-4j3r-vjvp · Severity: medium · Ecosystem: npm
— Open redirect in @auth0/nextjs-auth0
Affected software / configurations for CVE-2021-43812
Vendor
Product
Version
Raw CPE
auth0
nextjs-auth0
< 1.6.2
cpe:2.3:a:auth0:nextjs-auth0:*:*:*:*:*:node.js:*:*
References for CVE-2021-43812
cvelogic
Threat Intelligence